This is an application for a shared photometer, quantitative imaging microfluorometry, and microinjection system. The system is composed of an inverted photo microscope with brightfield, phase, DIC and incident fluorescence capability, a photometer, a video intensifier with a CCD camera operated at room temperature, video disc time lapse recorder, an image processor with 4 frames buffer, a programmable automated microscope stage with an automated microinjection system. The system will be linked to an existing computer network and data analysis will benefit from the Prophet Resource. All users have experience in quantitative microfluorescence on living cells or on liquid droplets and a majority of them are experienced in micromanipulation and microinjection. Quantitative microfluorescence, programmed automated stage, time lapse video recording and microinjection will be used to study: pH homeostasis in the early mammalian embryo, Ca2+. H+ and signalling pathways in glomerular cells, glutamine transport in the early mammalian embryo, function of ras p21 protein, ionic balance in hair cells, effect of heparin on mitogen induced proliferation, control of Na/H exchange by extracellular matrix, and fatty acid transport in the intestinal cell. Scheduling, new users, maintenance and future use will be reviewed by a local advisory committee.